Temperature-controlled press



March 22, 1966 E. SIEMPELKAMP 3,241,189

TEMPERATURE-C ONTROLLED PRES S Filed May 1, 1962 5 Sheets-Sheet 1 i UEUGEN SIEMPELKAMP INVENTOR BY gi AGENT March 22, 1966 E. SIEMPELKAMP3,241,189 I TEMPERATURE-CONTROLLED PRESS Filed May 1, 1962 5Sheets-Sheet 2 EUGEN SIEMPELKAMP INVENTOR.

March 22, 1966 E. SlEMPELKAMP TEMPERATURE-CONTROLLED PRESS 5Sheets-Sheet 3 Filed May 1, 1962 WQE mm Em m mv W nhm \m m Q Em f fiikmMl. -m- Km A in (66E ow m. QON

EUGEN SIEMPELKAMF INVENTOR.

AGENT March 22, 1966 Filed May 1, 1962 E.- SIEMPELKAMP 3,241,189

TEMPERATURE-C ONTROLLED PRES S 5 Sheets-Sheet 4.

6 H as" 70" 65/] II 66" 20d 71 FIG7 EUGEN SIEMPELKAMP INVENTOR.

BY 1' me United States Patent Claims. (c1. 1s 17 My present inventionrelates to a press, particularly (though not exclusively) one of themulti-level type, having means for subjecting its load to heating (or,in some instances, cooling) while compressing it between two platemembers such as a head plate and a bed plate of which at least one(usually the bed plate) is displaceable toward the other.

The head and bed plates of conventional presses advantageously have acellular structure with upper and lower flanges and interveningstiilening webs, e.g. in the form of two orthogonally intersectingarrays. Such presses can be used, e.g. as described in my copendingapplication Ser. No. 6,188 filed February 2, 1960 (now Patent No.3,050,777 issued April 28, 1962), for the heated compression and curingof cellulose-fiber sheets and similar compositions, for thevulcanization of rubber layers, and for a variety of other purposes. Asthe goods are maintained at elevated or subnormal tempratures during thecompression step, e.=g. with the aid of intermediate platens heated orchilled by a temperature-controlled fluid, care must be taken to preventa thermal deformation of the press plates due to the existence of amajor temperature difference between their proximal or inner and remoteor outer flanges. To this end it has heretofore been the practice tointerpose thermally insulating layers between the heated or cooledplatens and the head and bed plates; particularly in the case ofmulti-level presses with heated platens it has also been customary toinsert special cooling members between these plates and their insulatinglayers. Such arrangements are cumbersome, thermally uneconomical and notwholly reliable since the insulating layer tends to be weakened underthe operating pressure of the apparatus and to wear unevenly by' reasonof the often unavoidable non-uniform load distribution; also, the sharptemperature drop between the hot platen and the cooled press plate maylead to moisture condensation at the latter, with corrosive effects.

The general object of this invention is to provide improved means forsubstantially preventing thermal deformation of the relativelydisplaceable end plates in a press of the character described.

In accordance with this invention I provide, in a press having a pair ofrelatively displaceable end plates and at least twotemperature-controlled platens respectively adjoining these end plates,means for directly controlling the temperature of at least the outerflange of each plate in such manner as to maintain a temperaturediiierence of substantially invariable magnitude (including zero)between this outer flange and the platen adjacent its inner flange. Theconnection between the inner flange and the adjacent platen may be tightor loose; in the latter instant it will sometimes be desirable toprovide separate temperature-control means for the inner flange as well.In either instance there is no longer a need for interposing a thermalinsulation or additional temperaturestabilizing elements between thepress plate and its adjoining platen.

The temperature control may be carried out by any suitable means knownper se, including for example electric heating coils, yet I prefer toutilize the circulation of a heating or cooling fluid throughappropriate passages in the press flanges. Such a system has a highdegree of flexibility since it can be used for both heating and coolingpurposes, e.g. with alternation of fluids of dilierent temperaturesand/or the provision of separate channels for the selective passage of aheating medium or a coolant.

Whether the two flanges of a press plate are maintained at the sametemperature or at temperatures differing in a predetermined manner, theresult will always be the elimination of transient thermal stresseswhich would lead to undesirable deformation. The maintenance of asubstantially fixed temperature ditlerence may also be used for theestablishment of a particular curvature in the press plate Whose flangesare in such case longitudinally subdivided into several zonesindividually controlled as to temep-rature.

The invention will be described in greater detail with reference to theaccompanying drawing in which:

FIG. 1 is a somewhat schematic trontelevational view of a multi-platenpress similar to that shown in FIG. 2 of my above-identified Patent No.3,050,777;

FIG. 2 is a side-elevational view (parts broken away) of the press ofFIG. 1 in closed position, similar to FIG. 3 of the aforementionedcopending application;

FIG. 3 is a sectional plan view taken on the line III- III of FIG. 2;

FIG. 4 is a circuit diagram relating to the press of FIGS 1-3;

FIG. 5 is a diagrammatic view of the fluid-control system for the pressshown in FIGS. 1-3;

FIG. 6 is an alternate fluid-control diagram similar to FIG. 5;

FIG. 7 is a sectional elevational view of a part of a modified pressaccording to the invention;

FIG. 8 is another sectional elevational view, similar to FIG. 7,relating to a further embodiment;

FIG. 9 is a diagrammatic showing of a fluid-control system for the pressof FIG. 8; and

FIG. 10 is an elevational view of yet another press plate according tothe invention.

The press shown in FIGS. 1-3 is of the type wherein a plurality ofplatens 4 are raised and lowered by individual mechanical links hererepresented by cables 6, these cables being secured at one end to bars22 projec ing from the platens 4 and at the other end to suitabletransmission members constituted by four stepped pulleys 5 each having aset of cables associated with the several platens 4 connected thereto.The cables attached to the lowest platens engage the largest-diametersteps of each pulley 5 while the successively higher platens areconnected with respective smaller-diameter steps. Thus the pulleys, uponrotating, take up the cables in proportion to the required verticaldisplacement of each platen 4, thereby closing the press gradually andsmoothly and without requiring the bed plate 3 of the press or its lowerplatens to support upper, unloaded plat-ens. Rotation of the pulleys iscontrolled by a set of traction cables 7 (one for each pulley) which inturn are coupled with a hydraulic mechanism for elevating the bed plateas more fully described hereafter; upon the establishment of contactbetween two or more platens 4, through the intermediary of the sheets 21supported thereon or directly in the absence of such sheet, the tractionmechanism is inactivated so that the Working pressure is applied to thestack of platens 4 and sheets 21 directly by the bed plate 3 actingagainst a fixed head plate 2t) disposed next to the upper eross-member1' of the press frame 1. This avoids the development of mechanicalstrains which would otherwise occur in the differential cables 6 as theresult of unequal spacings caused, for example, by the absence of one ormore sheets '21 or by substantial differences in the thickness of theinserted sheets.

Each of the traction cables 7 passes under a respective idler pulley 38fixedly journaled in a bracket 57. The ends of cables 7 remote frompulleys are joined to a pair of yokes 17 extending at least partiallywithin and transverse to the bed plate 13, these yokes being elevatableby a pair of hydraulic cylinders 16b whose pistons 1.6a bear thereonfrom below. Bed plate 3 is also carried on pistons 2b of mastercylinders 2a which bear upon the lower cross-member 1' of frame 1. Anuppermost platen 4' and a lowermost platen 4" rest in the open positionof the press (FIG. 1) on fixed supports 58', 58", respectively, whichare rigid with the frame 1; in the normal position (bed plate 3 at itsbottom point) they are separated by a small clearance from the plates 3and 20, respectively.

Each intermediate platen 4 and the top platen 4' are provided with oneof a plurality of series-connected switches 41a-41h and one of aplurality of parallel-connected switches 37a37h which are closed by theengage ment of their armatures with the next-lower platen 4 or 4". Anormally closed limit switch 45 is mounted on the base of the press soas to be open-circuited upon the downstroke of yoke 17 by a stud 43carried thereon. The parallel combination of switches 37a-37h isconnected in series with the drive motor 44 of a hydraulic distributingvalve 40 and with a source 43 of electric current (see FIG. 4) while theseries-connected switches 41a41h are connected in a circuit including anelectromagnetic holding relay 55 and the battery 43. The relay contacts55a, 55b lie in series with battery 43 and with a set ofparallel-connected cylinders 12, whose function it is to release a setof pawls 11 from engagement with ratchet teeth 24 on the pulleys 5;switch 45 is inserted in the holding circuit of relay 55.

In operation, hydraulic fluid from a reservoir 27 is forced by a pump 28through a transmission tube 50 to the master cylinders 2a while a partof the fluid enters the cylinders 161) via a tube 52, thereby raisingthe yokes 17 and the bed 3. Advantageously, the flow of fluid is soregulated as to permit the yokes to raise the bed plate 3 at a rateequal to or faster than the speed of ascent of the pistons 2b so thatthese pistons remain spaced from the plate 3 until the pressure beginsto close, i.e. until one or more of the parallel switches 3712-3711operate. Upon such operation an electrical circuit is closed to drivemotor 44 which adjusts the distributing valve 40 to shut off the flow offluid to cylinder 16]) while continuing the flow under increasedpressure to master cylinders 2a. The upward motion of the yokes 17 thusceases whereas the bed plate 3 commences its compression stroke underthe urging of the pistons 211 now in contact with it, thereby slackeningthe cables 6 and 7 to disengage the spacer apparatus. At the conclusionof the compression stage, i.e. when all the sheets have been compressedto their predetermined thicknesses, the series-connected switches 41a to41h close to complete a circuit to the winding of relay 55, therebyclosing the contacts 55a, 55b and operating the solenoids 12 to withdrawthe pawls 11 from engagement with their ratchet rings 24. After apredetermined curing time has elapsed, the motor 44 in its continuingoperation blocks the fluid flow to cylinders 2a and opens a return pathfrom the latter to the reservoir 27 via return tube 56. The bed platethus commences to lower, entraining in the latter part of its descentthe yokes 17 to reactivate the spacer mechanism. The distributing valve44) may be designed to introduce fluid at this time to the tops ofcylinders 16b and 2a via tubes 53 and 51, respectively, to increase therate at which the press opens, at the same time withdrawing the pistons2b from contact with bed plate 3. As the yoke 17 and the bed plate 3attain the fully opened position of the press, plunger 43 trips thenormally closed switch 45 to deactivate the relay 55, thereby releasingpawls 11 and restoring the spacer assembly to operative conditionpreparatorily to a a new charge.

Abutments 57 (only one shown) on the frame 1 of the press serve assafety stops for the yokes 17 to insure a slackening of the cables uponfailure of the switching circuit 37a to 37/1.

As seen in FIGS. 2 and 3, each of the plates 3 and 20 consists of acellular structure which in the case of head plate 20 includes an outerflange 20a, an inner flange 2017, a multiplicity of transverse webs 20and intersecting array of longitudinal webs 20g; the correspondingelements of bed plate 3 have been designated 3a, 3b, 3 and 3g. Outer andinner flanges 20a and 2012 form the upper and lower surfaces,respectively, of head plate 20 whereas in the case of bed plate 3 theflanges are reversed. Each of the four flanges enumerated above isprovided with temperature-control means here shown by Way of example asset of fluid passages 200 in flange 20a, a similar set of passages 26din flange 29b, and analogous conduits 3c, 3d in flanges 3a and 3b,respectively. Similar passages 4a and 4a" are provided in the uppermostand lowermost platens 4 and 4" and may also be present in theintermediate platens 4. A thermally insulating hood 2% covers the topsurface and the sides of head plate 20, a similar hood 3e being providedfor the sides and the bottom surface of bed plate 3. No insulation ofany kind exists between plates 3 and 20 on the one hand and platens 4and 4" on the other.

It will be noted that the passages 20d and 3d, provided on the innerflanges of the respective plates, are more numerous (i.e. are of largertotal cross-sectional area) than the corresponding passages 20c and 30on the associated outer flanges. If these passages are traversed by thesame heating or cooling fluid as illustrated for passages 20c and 20d inFIG. 5, the inner flange will be heated or cooled more intensely thanthe outer flange whose fluid passages will have only a compensatingfunction to minimize or prevent thermal deformation of the plate. In thesystem of FIG. 5, for example, a pump 61 circulates atemperature-controlling fluid (preferably a coolant) through thecoinduits 20c and 20d in series, the fluid being maintained at thedesired temperature by a primary heating or cooling fluid in a conduit63. The passages 4a and 4a", shown to be as numerous as the passages 20dand 3d in the adjacent plate flanges 20b and 3b, may be included in thecirculation system of the flange passages by a connection in series orin parallel, eg as described hereinafter With reference to FIG. 9.

Each hydraulic piston 2b is provided at its top with a flange 2c whichcontains fluid passages 2d similar to those present in the bed and headplates 3 and 20. The con- H duits 2d may be traversed by a suitablecooling medium,

yet any heat transfer between flanges 2c and 3a will be negligible evenin the event of a large temperature difference therebetween since, apartfrom the relatively small area of the piston flange 2c, their surfacesare in contact with each other only during the brief interval when thepress is closed under hydraulic pressure from the cylinder 2a.

In FIG. 6 I have shown a modified circulation system for the passages20c and 20d adapted to maintain a predetermined temperature diiferencebetween the outer flange 20a and the inner flange 20b of head plate 20;again, a like system can be used for the corresponding flanges of bedplate 3. The conduits 20c and 20d are connected in FIG. 6 in twoseparate circuits each including a source (symbolized by respectivearrows 64', 64") and a sink (similarly symbolized by respective arrows65, 65") for a thermally controlled fluid, a valve 66', 66 regulatingthe rate of flow, an actuator 67, 67" for this valve and a controller68, 68" coupled with the respective actuator for maintaining a desiredflow rate as measured by a temperature feeler 69, 69", respectively. Thefeeler 69' or 69" works into the controller 68 or 68 which compares itsoutput with the setting of a manual regulator 70', 70"; the latter maybe a simple rheostat controlled by an indicator arm, this armco-operating with a scale 71', 71 preferably graduated in units oftemperature.

FIG. 7 illustrates the bed plate 3 and the head plate 20 of FIGS. 1-3 inthe absence of any intervening platens and without yokes 17. The pistons2b, which are here in permanent contact with the bed plate 3, arecovered atop their flanges 20 by a thermally insulating and resilientlayer 2e that flattens under the operating pressure of the hydrauliccylinders 2a so as to afford the mechanical equivalent of direct surfacecontact between the pistons and the bed plate. Normally, i.e. when onlythe dead weight of the plate 3 bears upon the resilient layers 2e, theirthickness is suflicient to minimize heat transfer between the lowerflange 3a of the bed plate and flanges 2c of the pistons provided withtheir respective fluid conduits 3c and 211'.

FIG. 8 illustrates a modified press according to the invention Whosehead plate 120 is in permanent contact with the uppermost platen 104'while the lowermost platen 104" similarly bears upon the bed plate 103.The plates 103 and 120 are of generally the same structure as theircounterparts in preceding figures, these plates being provided withouter flanges 103a and 120a, inner flanges 103b and 12012, transverseWebs 103 120 and longitudinal webs 103g and 120g. A thermally insulatingshell similar to hood 3e, 20e may be present but has not beenillustrated. In contradistinction to plates 3 and 20, however, theplates 103 and 120 contain fluid channels 103a and 120s only in theirouter flanges 103a and 120a; their inner flanges 103b and 12012 are freefrom such channels and are of solid structure. These inner flanges aremaintained at their proper temperatures (either at the same level as therespective outer flanges or with a predetermined temperature difference)by their contact with the platens 104 or 104" having fluid passages 104aand 104a". Bed plate 103 rests on pistons 10212 whose top flanges 102aare equipped with fluid passages 102d as in the preceding embodiments.

As illustrated in FIG. 9, the conduits 120s of head plate 120 and 104amay be connected in parallel between a fluid source (arrow 72) and afluid sink (arrow 73) via junctions 74 and 75, this ararngement insuringsubstantial uniformity of temperature throughout the platen structurewithout any special control device; a like arrangement is contemplatedfor the bed plate 103. It should be understood, however, thatcirculation systems of the type shown in FIGS. 5 and 6 could also beused. A separate fluid circuit, not shown, feeds the conduits 1020. ofpiston flanges 1020.

In some cases it will be desirable to make the temperature controlnon-uniform over the length of the head and/or bed plate. In such eventone may subdivide the flanges of these plates into a plurality ofadjoining heating or cooling zones with individual temperature controls.This has been illustrated in FIG. 10 for a head plate 220 whose upperand lower flanges are divided into zones 220a, 220a, 220a and 220b,2201), 220b', the associated fluid passages 220a, 220a, 2200 and 220d,

6 220d, 220d" being provided with individual regulators 268a, 268a, 268aand 268b, 268b, 26%" which may be similar to the devices 68 and 68 ofFIG. 6. It will be apparent that through proper temperature selectionfor the several flange zones a certain camber, e.g. upward as in FIG.10, may be imparted to the press plate.

The invention herein disclosed is believed to admit of manymodifications, including substitution or combination of equivalent orcompatible features from different embodiments, without departing fromthe spirit and scope of the appended claims. Certain features notclaimed in the present application are the subject matter of claims inmy copending application Ser. No. 192,038 filed on even date herewith.

I claim:

1. In a press having an upright frame with an upper and a lowercross-member and a plurality of relatively displaceable platens betweensaid cross-members for the compression of flat goods therebetween at atemperature different from ambient, the combination therewith of:

a fixed end member interposed between said platens and one of saidcross-members in direct contact with the latter, and a movable endmember interposed between said platens and the other of saidcrossmembers, each of said end members consisting of an outer flangeremote from said platens, an inner flange adjacent the respective one ofsaid platens and stiffening web means between said flanges, said outerand inner flanges being respectively provided with a first and a secondset of internal fluid passages uniformly distributed therein;

fluidoperated drive means bearing directly upon said movable end memberand said other of said crossmembers;

circulation means for passing a temperature-controlling fluid throughboth said first and second sets of passages of each of said end members;and

temperature-control means in said circulation means for individuallyregulating the temperatures of each of said flanges for preventingthermal deformation of said end members.

2. The combination defined in claim 1 wherein the total cross-sectionalarea of said second set of passages exceeds that of said first set ofpassages, said circulation means including a common fluid source forsaid first and second sets of passages.

3. The combination defined in claim 2 wherein each of said platens isprovided with a third set of fluid passages connected to said source,the total cross-sectional area of said second set of passages beingsubstantially equal to that of said third set of passages.

4. The combination defined in claim 1 wherein each of said flanges islongitudinally divided into zones, the respective temperature-controlmeans being correspondingly subdivided into individually adjust-ablesections for establishing predetermined temperature conditions thereinso as to impart a camber to said flanges.

5. In a press having an upright frame with an upper and a lowercross-member and a plurality of relatively displaceable platens betweensaid cross-members for the compression of flat goods therebetween at anelevated temperature, the combination therewith of:

a fixed end member interposed between said platens and one of saidcross-members in direct contact with the latter, and a movable endmember interposed between said platens and the other of saidcross-members, each of said end members consisting of an outer flangeremote from said platens, an inner flange adjacent the respective one ofsaid platens and stiffening web means between said flanges, said outerand inner flanges being respectively provided with a first and a secondset of internal fluid passages uniformly distributed therein;

fluid-operated drive means bearing directly upon said movable end memberand said Other of said cross members, said drive means including acooled piston in limited-area contact with said outer flange of saidmovable end member;

circulation means for passing a cooling fluid through both said firstand second sets of passages of each of said end members; and

temperature-control means in said circulation means for individuallyregulating the temperature of each of said flanges for preventingthermal deformation of said end members.

References Cited by the Examiner UNITED STATES PATENTS 2,779,969 2/1957Bose 18-17 X 2,941,249 6/1960 Rogers 1817 2,973,790 3/1961 Huetter l817X 3,050,778 8/1962 Jurgeleit 1817 OTHER REFERENCES German specificationDAS 1,033,223, published July J. SPENCER OVERHOLSER, Primary Examiner.

MICHAEL V. BRINDISI, WILLIAM J. STEPHENSON,

MARCUS U. LYONS, Examiners.

1. IN A PRESS HAVING AN UPRIGHT FRAME WITH AN UPPER AND A LOWERCROSS-MEMBER AND A PLURALITY OF RELATIVELY DISPLACEABLE PLATENS BETWEENSAID CROSS-MEMBERS FOR THE COMPRESSION OF FLAT GOODS THEREBETWEEN AT ATEMPERATURE DIFFERENT FROM AMBIENT, THE COMBINATION THEREWITH OF: AFIXED END MEMBER INTERPOSED BETWEEN SAID PLATENS AND ONE OF SAIDCROSS-MEMBERS IN DIRECT CONTACT WITH THE LATER, AND A MOVABLE END MEMBERINTERPOSED BETWEEN SAID PLATENS AND THE OTHER OF SAID CROSSMEMBERS, EACHOF SAID END MEMBERS CONSISTING OF AN OUTER FLANGE REMOTE FROM SAIDPLATENS, AN INNER FLANGE ADJACENT THE RESPECTIVE ONE OF SAID PLATENS ANDSTIFFENING WEB MEANS BETWEEN SAID FLANGES, SAID OUTER AND INNER FLANGESBEING RESPECTIVELY PROVIDED WITH A FIRST AND A SECOND SET OF INTERNALFLUID PASSAGES UNIFORMLY DISTRIBUTED THEREIN; FLUID-OPERATED DRIVE MEANSBEARING DIRECTLY UPON SAID MOVABLE END MEMBER AND SAID OTHER OF SAIDCROSSMEMBERS;